Torque-transmitting, variably-flexible, locking insertion device and method for operating the insertion device

ABSTRACT

A torque-transmitting, variably-flexible, locking insertion device includes a hollow body having a proximal end with an entrance for receiving an instrument, a distal end with a tip for protrusion of the instrument, and a handle to be gripped by an operator. A device locks the handle to and unlocks the handle from the instrument, which is at least partly disposed within the hollow body. A device transitions the hollow body between a relatively flexible condition and a relatively stiff condition. A method for operating a torque-transmitting, locking insertion device includes placing the instrument at least partly within the hollow body and locking the handle to and unlocking the handle from the instrument. The hollow body is transitioned between a relatively flexible condition and a relatively stiff condition.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a torque-transmitting, variably-flexible, locking insertion device. The invention also relates to a method for operating the insertion device.

2. Description of the Related Art

Prior art insertion devices of this general type cannot be connected to an instrument, such as an endoscope or a colonoscope, in such a manner as to be reliable and sufficiently torque-transmitting, while at the same time being easily releasable therefrom and variably flexible. The operator of the device must have the ability to manipulate the instrument when necessary with the insertion device and yet free the instrument easily when necessary.

Devices produced by Spirus Medical, Inc. under the designations Endo-Ease advantage, Endo-Ease discovery and Endo-Ease vista are lightly engaged to and disengaged from a colonoscope and rotate independently thereof. The devices have a spiral at the distal end to follow the lumen of the colon or small bowel when rotated and pushed forward. All three devices have a fixed and predetermined greater flexibility at the distal end and lesser flexibility at the proximal end.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a torque-transmitting, variably-flexible, locking insertion device and a method for operating the insertion device, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and which permit an operator of the device to easily and reliably lock the insertion device to and unlock the insertion device from an instrument while varying stiffness.

With the foregoing and other objects in view there is provided, in accordance with the invention, a torque-transmitting, locking insertion device. The insertion device comprises a hollow body having a proximal end with an entrance for receiving an instrument, such as a scope, a distal end with a tip for protrusion of the instrument, and a handle to be gripped by an operator. A device locks the handle to and unlocks the handle from the instrument, which is at least partly disposed within the hollow body. A device, which may be vacuum activated, transitions the hollow body between a relatively flexible condition and a relatively stiff condition.

With the objects of the invention in view, there is also provided a method for operating a torque-transmitting, locking insertion device. The method comprises providing a hollow body having a proximal end with an entrance for receiving an instrument, such as a scope, a distal end with a tip for protrusion of the instrument, and a handle to be gripped by an operator. The instrument is placed at least partly within the hollow body and the handle is locked to and unlocked from the instrument. The hollow body is transitioned between a relatively flexible condition and a relatively stiff condition, such as by vacuum activation.

Thus, through the use of the invention, an operator of the insertion device can not only lock the device to and unlock the device from an instrument, but can also transition the device between relatively flexible and relatively stiff conditions, while applying torque and axial movement to the instrument.

In accordance with another feature of the invention, the locking and unlocking device includes an actuator to be activated by the operator for locking the handle to and unlocking the handle from the instrument. The actuator may be a bobbin to be slid onto the handle by the operator. The locking and unlocking device may also include a clamping plate disposed within the actuator. The clamping plate is moved radially inwardly against the instrument and radially outwardly away from the instrument by activating the actuator. This structure provides a simple and easy to use locking device, which nevertheless delivers reliable locking of an instrument while transmitting torque and advancing axially.

In accordance with a further feature of the invention, the clamping plate includes a plurality of partial-plates, at least one spring biasing the partial-plates radially outwardly and detents integral with the partial-plates. The detents are disposed in recesses in the actuator in a non-actuated condition and slide out of the recesses and push the partial-plates towards the instrument against a force of the at least one spring into an actuated condition. A body tube is disposed partially within the actuator and partially within the handle. The body tube has slots formed therein within which the detents slide between the actuated and non-actuated conditions. The handle has a collar limiting motion of the actuator into the actuated condition. Although the plates, detents and springs are simple elements, they produce reliable locking between the handle and the bobbin.

In accordance with an added feature of the invention, a corrugated tube transmits torque from the proximal end toward the distal end. An inner sleeve disposed within the corrugated tube prevents vacuum leakage and aids in insertion of the instrument. Tendons are disposed along the corrugated tube within the hollow body for maintaining the hollow body in the relatively flexible and relatively stiff conditions.

In accordance with an additional feature of the invention, the hollow body has an outer jacket, the tendons are at least partly disposed between the outer jacket and the corrugated tube, and the transitioning device applies suction between the outer jacket and the corrugated tube for frictionally locking the tendons in place. The corrugated tube provides a certain inherent stiffness, which can be greatly increased by the operator of the insertion device by locking the tendons between the outer jacket and the corrugated tube.

In accordance with yet another feature of the invention, a coupler disposed within the handle defines a vacuum plenum volume therebetween. The handle has a vacuum inlet/outlet hole formed therein communicating with the vacuum plenum volume.

In accordance with yet a further feature of the invention, a sliding valve encircles the handle and has a vacuum inlet/outlet formed therein for communicating with the vacuum connection. The sliding valve slides between a position in which the vacuum inlet/outlet communicates with the vacuum inlet/outlet hole and a position in which the vacuum inlet/outlet is sealed against the vacuum inlet/outlet hole. Thus, the variation in stiffness is provided by simply applying and releasing vacuum when desired by the operator.

In accordance with a concomitant feature of the invention, vertebrae are disposed along the corrugated tube, between corrugation peaks, for guiding the tendons. The vertebrae include at least one last vertebra closest to the distal end. Each two of the tendons form legs of a U-shaped configuration passing through holes in the vertebrae and being interconnected by a crosspiece distally of the last vertebra. There may be two last vertebrae between which the crosspiece is fixed. The tendons may vary in number along the hollow body for providing zones of varying stiffness. The tendons float when the hollow body is in the relatively flexible condition. The tendons are not in tension or compression when the hollow body is in the relatively stiff condition. The tendons are not under tension in both the relatively flexible and relatively stiff conditions. The combination of the vertebrae and the tendons provide inherent stiffness to the degree desired, while permitting added stiffness to be attained by the transitioning device.

Other features which are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in a torque-transmitting, variably-flexible, locking insertion device and a method for operating the insertion device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic, perspective view of a torque-transmitting, variably-flexible, locking insertion device according to the invention;

FIG. 2 is a perspective view similar to FIG. 1, showing a working length of the insertion device;

FIG. 3 is an enlarged, perspective view of the insertion device, showing details of a proximal end;

FIG. 4 is a fragmentary, further enlarged, top-plan view of the proximal end of the insertion device;

FIG. 5 is an even further enlarged, fragmentary, side-elevational view of the proximal end of the insertion device;

FIG. 6 is a perspective view of the insertion device with an outer jacket removed;

FIG. 7 is a fragmentary, enlarged, side-elevational view of the proximal end and part of the working length of the insertion device with the outer jacket removed;

FIG. 8 is a view similar to FIG. 6, of the insertion device with a lock in an actuated condition;

FIGS. 9A and 9B are even further enlarged, fragmentary, elevational views of a distal end of the insertion device in which a locking ring is respectively shown and omitted for clarity and in which the outer jacket has been removed;

FIGS. 10A and 10B are fragmentary, perspective views of the distal end of the insertion device in which the locking ring is respectively shown and omitted for clarity and in which the outer jacket has been removed;

FIGS. 11A, 11B and 11C are fragmentary, longitudinal-sectional views of the distal end of the insertion device with the outer jacket removed and respectively showing two locking rings, one locking ring and no locking ring;

FIG. 12 is an exploded, perspective view of the insertion device;

FIG. 13 is a fragmentary, longitudinal-sectional view of the proximal end and part of the working length of the insertion device;

FIG. 14 is a greatly enlarged, fragmentary, side-longitudinal-sectional view of a proximal section of the insertion device;

FIG. 15 is a fragmentary, top-longitudinal-sectional view of the proximal section of the insertion device;

FIG. 16 is a fragmentary, side-longitudinal-sectional view of the proximal end of the insertion device;

FIG. 17 is a fragmentary, top-longitudinal-sectional view of the proximal end of the insertion device in the actuated condition;

FIG. 18 is a fragmentary, top-longitudinal-sectional view of the proximal end of the insertion device similar to FIG. 17, in a non-actuated condition; and

FIGS. 19A, 19B, 19C and 19D are enlarged, fragmentary, perspective views of the proximal end of the insertion device respectively showing a handle with a clamping plate, a body tube slid over the clamping plate, an end cap at the proximal end and a bobbin distally of the end cap.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawings in detail and first, particularly, to FIGS. 1 and 2 thereof, there is seen a torque-transmitting, variably-flexible, locking insertion device 1 according to the invention having a working length. The insertion device 1 has a hollow body with a proximal end 2 for manipulation by an operator and for receiving an instrument 40 such as an endoscope or a colonoscope, shown in FIG. 13. The insertion device 1 also has a distal end 3 for insertion into a patient and for protrusion of the instrument. A handle 4 of the hollow body for control by the operator is disposed at the proximal end 2. An outer jacket or sleeve 5 of the hollow body extends to a tip 6, which may be formed of rubber, at the distal end 3. As will be explained below, the handle 4 has an end cap 8, an actuator or bobbin 9 for locking an instrument, a sliding valve or slider 10 and a forward stop 11. The handle 4 also has a vacuum connection or nipple 12 for controlling stiffness of the device, as will be explained below as well. A corrugated tube 15 in the region of the distal tip 6, which is illustrated in other figures, extends to the coupler 35.

FIGS. 3, 4 and 5 are enlarged perspective, top and side views showing the insertion device 1, from which the end cap 8, the actuator or bobbin 9, the handle 4, the sliding valve or slider 10 with the nipple 12, the forward stop 1 and the strain relief retainer 7, can be seen more clearly. FIG. 3 also shows the outer jacket 5 and the distal tip 6.

FIGS. 6 and 8 are perspective views of the entire insertion device 1 and FIG. 7 is a fragmentary side view of the proximal end and part of the working length of the insertion device, in which the outer jacket 5 has been removed. It can therefore be seen that the corrugated tube 15 extends distally beyond the strain relief retainer 7 to the tip 6 and that vertebrae 16 are clipped between several of the corrugations. Although only five vertebrae are shown in FIGS. 6 and 8, as many as twelve or more may be provided, depending on the working length and the application for which the insertion device is intended. The vertebrae may have slits formed radially therein to aid in slipping them over the corrugated tube. The last vertebra in the distal direction is a locking ring or termination vertebra 17. Whereas FIGS. 6 and 7 show the insertion device in the unlocked condition, FIG. 8 shows it in the locked condition, which will be discussed in more detail below. FIGS. 6, 7 and 8 also show staples or tendons 18 extended axially along the outer periphery of the corrugated tube 15.

As is seen in the fragmentary side, perspective and longitudinal-sectional views of FIGS. 9A and 9B, 10A and 10B and 11A, 11B and 11C, the tendons or staples 18 are looped through holes or slits 22 in the vertebrae 16 and the locking ring 17. The locking rings 17 have been omitted in FIGS. 9B and 10B to show details of the tendons or staples 18. The tendons or staples 18 have ends 19 extending proximally, as shown in FIG. 12. The tendons or staples 18 may be fixedly connected to the locking ring 17, such as by adhesive, weldments or solder joints. However, FIGS. 9B and 11A, 11B and 11C show that the tendons or staples 18 have a U-shape with legs passing through the holes 22 in the vertebrae 16 and cross pieces 20 disposed just distally beyond the locking ring 17. It can be seen particularly clearly in FIG. 11A that the cross pieces 20 of the tendons or staples 18 are captured and prevented from migrating distally by two locking rings 17 between which the cross pieces H are sandwiched in a valley or trough between two peaks or crests of the corrugated tube 15.

The number and location of the tendons or staples 18 and the vertebrae 16 axially and circumferentially may be chosen in such a way as to vary the stiffness of the insertion device 1 in zones. For example, more tendons or staples 18 and/or more vertebrae 16 may be placed in one zone along the working length than in another zone. The zone with more tendons or staples and/or vertebrae will be stiffer. Additionally, some of the tendons or staples may not extend over the entire working length and some may be fixed to vertebrae along the working length, all of which also varies stiffness in zones. As the insertion device flexes, some of the tendons or staples which are not fixed to particular vertebrae slide in the holes or slits 22.

The exploded view of FIG. 12 and the assembled sectional view of FIG. 13 show the end cap 8 at the proximal end, which surrounds a rear bushing 16. It may be seen that a marker band 28 is disposed between the actuator or bobbin 9 and the end cap 8. A clamping plate 30, which is also disposed within the actuator or bobbin 9, has three partial-plates 31 a, 31 b, 31 c between which three springs 32 are disposed. A body tube 33, having slots 51, is disposed distally of the clamping plate 30.

A coupler 35, having grooves 23 extended axially on the periphery thereof, carries a septum seal 37 and an O-ring 38 provides a seal between the coupler 35 and the handle 4, which is slid over the coupler 35. Other marker bands 29 are disposed between the handle 4 and the sliding valve or slider 10 and the forward stop 11 is disposed over the distal end of the handle 4. O-rings 24 provide a seal between the slider 10 and the handle 4. An O-ring 34 is disposed between the forward stop 11 and the handle 4. It may also be seen that a heat shrink tubing 39 covers the coupler 35 and an inner liner or sleeve 36 is disposed within the corrugated tube 15. Moving distally, the corrugated tube 15 carrying the vertebrae 16, the tendons or staples 18, the locking ring 17 and the distal tip 6, is shown as well.

The inner sleeve 36 provides a surface over which the instrument 40 will pass smoothly within the corrugated tube 15. The corrugated tube 15 may be formed of nylon or another suitable material. The inner sleeve 36 may be made from a sheet of polyester film, which has an adhesive coating on one side. The inner sleeve 36 is rolled around an inflatable mandrel and heated in an oven, to form a bonded seam and is sealed to an inner surface of the corrugated tube 15. The corrugations of the corrugated tube 15 have peaks and valleys, as mentioned above. As viewed from within the corrugated tube 15, the inner sleeve 36 adheres to the peaks and extends somewhat into the valleys of the corrugations as dimples. Therefore, as the insertion device bends, the inner sleeve 36 stays tight along the corrugations on the outside of the bend and crinkles at the inside of the bend. The peaks and valleys of the corrugations also need not be of equal length along the length of the corrugated tube 15. For example, 70% of the length may be peaks and 30% valleys or 80% of the length may be peaks and 20% valleys. These variations will add to the adhesion of the inner sleeve 36 to the corrugated tube 15 and reduce the formation of dimples. However, a 50/50 corrugation ratio is shown in the figures.

The outer jacket 5 may be formed of polyurethane or another suitable material which is similarly a flat sheet that is rolled and seamed. The outer jacket 5 extends to the distal tip 6 and the inner sleeve 36 terminates with the end of the corrugated tube 15, the ends of which are “cuffed” to allow attachment of components.

The sectional views of FIGS. 14 and 15 show greater detail of the construction of the slider or sliding valve 10 having the nipple 12. The slider 10, which encircles the handle 4, has a sliding so-called tire valve thumb grip 13 and is sealed thereto by the O-rings 24 which are disposed in recesses 14 in the handle 4.

It may be seen that the handle 4 and the coupler 35 define an annular vacuum plenum volume 41 therebetween which extends in longitudinal direction of the handle 4. The O-ring 2 provides a seal at the proximal end of the volume 41. A vacuum inlet/outlet hole or port 42 is formed in the body of the handle 4 and communicates with the volume 41. The sliding valve or slider 10 also has a vacuum inlet/outlet 43 for the connection or nipple 12. When the slider 10 is slid toward an annular stop 44, the vacuum inlet/outlet 43 is not in alignment with the vacuum inlet/outlet hole 42. However, when the slider 10 is slid toward an annular stop 45, the vacuum inlet/outlet 43 and the vacuum inlet/outlet hole 42 are aligned, providing communication between the connection or nipple 12 and the volume 41. Therefore, during operation, the slider 10 is slid toward the stop 45 to apply vacuum to stiffen the hollow body. The slider 10 is slid toward the stop 44 to vent the vacuum to atmospheric pressure making the hollow body flexible again.

When vacuum is applied to the volume 41 in the manner described above, the outer jacket 5 and the corrugated tube 15 approach each other with the staples or tendons 18 sandwiched and frictionally locked therebetween. Therefore, the vacuum connection or nipple 12 acts as a device for transitioning the hollow body 4, 6, 35, 5, 36, between a relatively flexible condition and a relatively stiff condition through the application of a vacuum. As long as the vacuum is applied, the insertion device 1 maintains it condition, whether flexed or straight. When it is desired to resume flexibility of the insertion device 1, the vacuum is vented or replaced by air at ambient or positive pressure. This causes the corrugated tube 15 and the outer jacket 5 to release the tendons or staples 18 and the corrugated tube 15 and allows the inherent stiffness of the corrugated tube 15 to place the insertion device 1 into its normally flexible condition.

The tendons, staples or wires 18 are passive elements which are not in tension at any time. The tendons or staples float within the hollow body 4, 6, 35, 5, 36, 15 when it is in the flexible condition, except where they are fixed to the locking rings 17. The tendons or staples are frictionally locked by the corrugated tube 15 and the outer jacket or sleeve 5 when the hollow body is in the stiff condition. However, in both the relatively flexible condition and the relatively stiff condition, the tendons or staples have no active control imposed on them and are not pulled or constrained.

As mentioned above, a comparison between FIGS. 6 and 8 reveals that the actuator or bobbin 9 in FIG. 6 is adjacent the end cap 8 in a non-actuated condition, while in FIG. 8 the actuator or bobbin 9 is in an actuated condition, in which it has been moved over an extension 47 of the handle 4 and against a collar 48 of the handle 4. FIGS. 16 and 18 also show the actuator or bobbin 9 in the non-actuated condition, whereas FIG. 17 shows the actuator or bobbin in the actuated condition, but in greater detail.

As is seen in FIGS. 12-13, 16-18 and 19A, 19B and 19C, the three partial-plates or partial-shells 31 a, 31 b, 31 c of the clamping plate 30 have detents 50 protruding therefrom. FIGS. 17, 18 and 19A, 19B and 19C in particular show that the springs 32 bias the partial-plates and therefore the detents 50 through slots 51 in the body tube 33 and into corresponding recesses 52 in the inner peripheral surface of the actuator or bobbin 9 in the non-actuated condition. When a sliding, so-called tire valve thumb grip 53 of the actuator or bobbin 9 is pushed by the operator of the device and the actuator or bobbin is slid distally toward the collar 48 of the handle 4, the detents 50 slide out of the recesses 52 against the force of the springs 32. This causes the partial-plates 31 a, 31 b, 31 c to move toward each other radially and against the instrument 40, such as an endoscope or a colonoscope represented by a dot-dash line in FIG. 13, for holding the instrument in place. When the actuator or bobbin 9 is slid proximally, the detents 50 once again fall into the recesses 52 due to the force of the springs 32, so that the partial-plates 31 a, 31 b, 31 c move radially outwardly and release the instrument 40. Therefore, the actuator or bobbin 9 and the clamping plate 30 form a locking and unlocking device to be activated by the operator for locking the handle 4 to and unlocking the handle 4 from the instrument 40.

FIGS. 16, 17 and 18 also show the septum seal or valve assembly 37 in greater detail, as well as the end cap 8 which is inserted into the proximal end of the handle 1. End caps 8 with various sized openings may be used in dependence on the instrument being used. The instrument passes through the hollow body and emerges at the distal tip 6. It may be seen that the septum seal or septum valve assembly 37 has a diaphragm 37′ resting in a recess in the coupler 35.

A comparison of FIGS. 19A, 19B, 19C and 19D also shows that in FIG. 19A merely the handle 4 with the extension 47 and the collar 48 as well as the partial-plates 31 a, 31 b, 31 c are shown, while the body tube 33 has been slid over the partial-plates in FIG. 19B, the end cap 8 has been added at the proximal end in FIG. 19C and the actuator or bobbin 9 has been added distally of the end cap in FIG. 19D.

The insertion device is intended to be used in a manner similar to prior art devices. Therefore, the insertion device will be placed over the endoscope. The endoscope will then be inserted into the rectum. The insertion device will then be pushed in its flexible condition, to follow the curvature of the scope. The insertion device will then be stiffened, allowing the scope to be pushed forward with less pressure exerted on the colon of the patient. This procedure can be repeated until the scope reaches the cecum.

An alternative use of the insertion device is to aid in small bowel endoscopy. The insertion device is placed over the endoscope. The endoscope is inserted into the patient transorally, through the stomach and then partially into the small bowel. The insertion device is then pushed in its flexible condition, to follow the curvature of the scope. The insertion device is then stiffened, allowing the scope to be pushed forward without the scope looping in the stomach.

Another use of the insertion device is for aiding in access to internal body parts, such as the gallbladder, through an opening of an internal body cavity, such as the stomach. The insertion device is placed over the endoscope. The endoscope is inserted into the patient transorally, through the stomach and then up against the internal surface of the stomach. The insertion device is then pushed in its flexible condition, to follow the curvature of the scope. The insertion device is then stiffened, allowing the surgeon to create an opening in the stomach wall without the scope looping in the stomach. Once the opening is created, the insertion device and the scope can be advanced outside the stomach. The insertion device can then be stiffened to create a stable platform to perform surgical procedures outside of the stomach. The insertion device could contain one or more features (i.e. balloons) for sealing the outer periphery of the insertion device to the stomach wall to prevent gastric fluids from exiting the stomach. 

1. A torque-transmitting, variably-flexible, locking insertion device, comprising: a hollow body having a proximal end with an entrance for receiving an instrument, a distal end with a tip for protrusion of the instrument, and a handle to be gripped by an operator; a device for locking said handle to and unlocking said handle from the instrument at least partly disposed within said hollow body; and a device for transitioning said hollow body between a relatively flexible condition and a relatively stiff condition.
 2. The insertion device according to claim 1, wherein said locking and unlocking device includes an actuator to be activated by the operator for locking said handle to and unlocking said handle from the instrument.
 3. The insertion device according to claim 2, wherein said actuator is a bobbin to be slid onto said handle by the operator.
 4. The insertion device according to claim 2, wherein said locking and unlocking device includes a clamping plate disposed within said actuator, said clamping plate being moved radially inwardly against the instrument and radially outwardly away from the instrument by activating said actuator.
 5. The insertion device according to claim 4, wherein said clamping plate includes a plurality of partial-plates, at least one spring biasing said partial-plates radially outwardly and detents integral with said partial-plates, said detents disposed in recesses in said actuator in a non-actuated condition and sliding out of said recesses and pushing said partial-plates towards the instrument against a force of said at least one spring into an actuated condition.
 6. The insertion device according to claim 5, which further comprises a body tube disposed partially within said actuator and partially within said handle, said body tube having slots formed therein within which said detents slide between said actuated and non-actuated conditions.
 7. The insertion device according to claim 5, wherein said handle has a collar limiting motion of said actuator into said actuated condition.
 8. The insertion device according to claim 1, wherein said transitioning device is vacuum activated.
 9. The insertion device according to claim 8, which further comprises a corrugated tube for transmitting torque from said proximal end toward said distal end.
 10. The insertion device according to claim 9, which further comprises an inner sleeve disposed within said corrugated tube for preventing vacuum leakage and aiding in insertion of the instrument.
 11. The insertion device according to claim 9, which further comprises tendons disposed along said corrugated tube within said hollow body for maintaining said hollow body in said relatively flexible and relatively stiff conditions.
 12. The insertion device according to claim 11, wherein said hollow body has an outer jacket, said tendons are at least partly disposed between said outer jacket and said corrugated tube, and said transitioning device applies suction between said outer jacket and said corrugated tube for frictionally locking said tendons in place.
 13. The insertion device according to claim 12, wherein said transitioning device includes a vacuum connection.
 14. The insertion device according to claim 13, which further comprises a coupler disposed within said handle and defining a vacuum plenum volume therebetween, said handle having a vacuum inlet/outlet hole formed therein communicating with said vacuum plenum volume.
 15. The insertion device according to claim 14, which further comprises a sliding valve encircling said handle and having a vacuum inlet/outlet formed therein for communicating with said vacuum connection, said sliding valve sliding between a position in which said vacuum inlet/outlet communicates with said vacuum inlet/outlet hole and a position in which said vacuum inlet/outlet is sealed against said vacuum inlet/outlet hole.
 16. The insertion device according to claim 15, wherein said handle has a recess formed therein receiving an O-ring for sealing said sliding valve to said handle.
 17. The insertion device according to claim 11, which further comprises vertebrae disposed along said corrugated tube for guiding said tendons.
 18. The insertion device according to claim 17, wherein said vertebrae are disposed between corrugation peaks of said corrugated tube for guiding said tendons.
 19. The insertion device according to claim 17, wherein said vertebrae include at least one last vertebra closest to said distal end, each two of said tendons forming legs of a U-shaped configuration passing through holes in said vertebrae and being interconnected by a crosspiece distally of said last vertebra.
 20. The insertion device according to claim 19, wherein said at least one last vertebra are two last vertebrae between which said crosspiece is fixed.
 21. The insertion device according to claim 11, wherein said tendons vary in number along said hollow body for providing zones of varying stiffness.
 22. The insertion device according to claim 11, wherein said tendons float when said hollow body is in said relatively flexible condition.
 23. The insertion device according to claim 11, wherein said tendons are not in tension or compression when said hollow body is in said relatively stiff condition.
 24. The insertion device according to claim 11, wherein said tendons are not under tension in both said relatively flexible and relatively stiff conditions.
 25. The insertion device according to claim 1, wherein the instrument is a scope.
 26. A method for operating a torque-transmitting, variably-flexible, locking insertion device, the method comprising the following steps: providing a hollow body having a proximal end with an entrance for receiving an instrument, a distal end with a tip for protrusion of the instrument, and a handle to be gripped by an operator; placing the instrument at least partly within the hollow body; and locking the handle to and unlocking the handle from the instrument; and transitioning the hollow body between a relatively flexible condition and a relatively stiff condition.
 27. The method according to claim 26, which further comprises carrying out the locking and unlocking step with a device having an actuator to be activated by the operator.
 28. The method according to claim 27, wherein the actuator is a bobbin to be slid onto the handle by the operator.
 29. The method according to claim 27, wherein the locking and unlocking device includes a clamping plate disposed within the actuator, and the locking and unlocking step includes moving the clamping plate radially inwardly against the instrument and radially outwardly away from the instrument by activating the actuator.
 30. The method according to claim 29, wherein the clamping plate includes a plurality of partial-plates, at least one spring biasing the partial-plates radially outwardly and detents integral with the partial-plates, and the locking and unlocking step includes placing the detents in recesses in the actuator in a non-actuated condition and sliding the detents out of the recesses to push the partial-plates towards the instrument against a force of the at least one spring into an actuated condition.
 31. The method according to claim 30, which further comprises sliding the detents in slots formed in a body tube disposed partially within the actuator and partially within the handle when moving the actuator between the actuated and non-actuated conditions.
 32. The method according to claim 30, which further comprises limiting motion of the actuator into the actuated condition with a collar on the handle.
 33. The method according to claim 26, which further comprises transmitting torque along the hollow body with a corrugated tube.
 34. The method according to claim 33, which further comprises applying suction to create a vacuum in the hollow body for placing the hollow body in the relatively stiff condition, and relieving the vacuum for placing the hollow body in the relatively flexible condition.
 35. The method according to claim 33, which further comprises preventing vacuum leakage and aiding in insertion of the instrument with an inner sleeve disposed within the corrugated tube.
 36. The method according to claim 35, which further comprises adhesively connecting the inner sleeve to the corrugated tube.
 37. The method according to claim 34, which further comprises maintaining the hollow body in the relatively flexible and relatively stiff conditions with tendons disposed within the hollow body.
 38. The method according to claim 37, which further comprises providing the hollow body with an outer jacket, providing the tendons at least partly between the outer jacket and the corrugated tube, and carrying out the step of applying suction between the outer jacket and the corrugated tube with a transitioning device for frictionally locking the tendons in place.
 39. The method according to claim 38, which further comprises providing a vacuum connection as the transitioning device, and actuating the vacuum connection with a valve at the handle.
 40. The method according to claim 37, which further comprises guiding the tendons with vertebrae disposed along the corrugated tube.
 41. The method according to claim 40, which further comprises placing the vertebrae between corrugation peaks of the corrugated tube for guiding the tendons.
 42. The method according to claim 40, which further comprises permitting movement of at least some of the tendons through holes formed in at least some of the vertebrae.
 43. The method according to claim 40, which further comprises providing at least one of the vertebrae as a last vertebra closest to the distal end, and forming each two of the tendons into legs of a U-shaped configuration passing through holes in the vertebrae and being interconnected by a crosspiece distally of the last vertebra.
 44. The insertion device according to claim 43, wherein the at least one last vertebra are two last vertebrae between which the crosspiece is fixed.
 45. The method according to claim 40, which further comprises varying the number of the tendons along the corrugated tube for providing zones of varying stiffness. 